Structural analysis of the exopolysaccharides produced by Lactobacillus spp. G-77.

The exopolysaccharide produced by a ropy strain of Lactobacillus spp. G-77 in a semi-defined medium, was found to be a mixture of two homopolymers composed of D-Glc. The two poly-saccharides were separated and, on the basis of monosaccharide and methylation analyses, 1H, 13C, 1D and 2D NMR experiments, one of the polysaccharides was shown to be a 2-substituted-(1-3)-beta-D-glucan, identical to that described for the EPS from Pediococcus damnosus 2.6 (M.T. Dueñas-Chasco, M.A. Rodríguez-Carvajal, P. Tejero-Mateo, G. Franco-Rodríguez, J. L. Espartero, A. Irastorza-Iribar, and A.M. Gil-Serrano, Carbohydr. Res., 303 (1997) 453-458), and the other polysaccharide was shown to consist of repeating units with the following structure [formula: see text]